IEnumerable over a Generic List?

I have a Card.cs class that has a card built with a few enum properties. I can make my cards just fine and can select some stuff with LINQ. I have a second class called Deck.cs. This is where I am currently messing up.

This just doesn't sit right… I know this is a pile and want to know what people should recommend I read from here. Any suggestions? I think in Deck.cs I want to implement IEnumerable<List<Card>> . Does that sound right at all…?